Field of the Invention
The invention generally relates to an image processing apparatus, and particularly, to an image processing apparatus for compensating an image transmission rate.
Description of Related Art
Along with the evolution of the electronic technology, for the convenience of capture and transmission of information, high performance image capture device has been essential component of an electronic device.
During an image capture process, image is usually transmitted to an image capture device via air. During such transmission, the quality of the image transmitted to the image capture device may be varied due to an image transmission rate of the air at the time which the image was transmitted. Especially, in outdoor environment, the air may contain smog or haze, which would blur the captured image and causes problems such as deterioration in quality, poor contrast, color distortion, etc.
Conventionally, an estimation of a transmission map is performed to an input image, and compensation to such effect is performed according to the transmission map. Herein, the transmission map includes a plurality of values, where each of the values corresponds to each pixel in the input image and represents a distortion status of the corresponding pixel resulted from the transmission of the image to the image capturing device. However, the estimations of the transmission map are often erroneous due to the color of the object in the image and brightness of the image. For example, the transmission map of an object having color similar to the color of atmosphere are under estimated. The estimation of the transmission rate of the low brightness object would come out to be higher (the estimation of the transmission rate of the high brightness object would come out to be lower), which results in a contradiction where different transmission rates may be estimated for the same object. Therefore, the effect of the conventional de-haze process is unsatisfactory.